<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <script>
        'use strict';

        console.log('a');
        console.log("a");
        console.log("\u4e2d");  //Unicode字符
        console.log("\x41");    //ASCII字符

        // Tab键上面 ESC键下面
        let msg = `
            hello
            world
            你好
            世界
        `;

        console.log(msg);

        let name = "xiaoming";
        let age = 3;
        let msg1 = `你好呀，${name}`;

        console.log(msg1);

        //字符串长度
        console.log(msg1.length);

        //大小写转换
        console.log(msg1.toUpperCase());

        console.log(msg1.indexOf('x'));

        //字符串截取
        console.log(msg1.substring(1));     // 从第一个字符串截取到最后一个字符串
        console.log(msg1.substring(1,3));   // [1,3)

    </script>

</head>
<body>

</body>
</html>